Reaxis®  C221 - Dibutyltin Dineodecanoate

REAXIS® C221 (Dibutyltin Dineodecanoate) is a butyl-based organotin used most commonly as a catalyst for polyurethane and silicone condensation reactions. The presence of the neodecanoate ligand and percentage of active tin metal make Dibutyltin Dineodecanoate  a suitable candidate across a broad spectrum of formulations. The octyl analogue of REAXIS® C318 would be REAXIS® C316 (Dioctyltin Dineodecanoate), and the methyl analogue is REAXIS® C325 (Dimethyltin Dineodecanoate).    Alternative butyl derivatives would include REAXIS® C233 (Dibutyltin Diacetate), REAXIS® C218 (Dibutyltin Dilaurate) and REAXIS® C317 (Dibutyltin bis-(2-ethylhexyl Maleate). Inorganic tin alternatives would include REAXIS® C125 (Stannous Neodecanoate) and REAXIS® C129 (Stannous Octoate). All the above-mentioned products are neat liquids with varying metal content and ligand makeup.

For more information, we invite you to read our technical bulletin on Iron Catalysts.

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Technical Information

  • Product Category Organotin

  • Chemical Name Dibutyltin Dineodecanoate

  • CAS Number 25168-22-3

Typical Specifications

Parameter Range
Tin Content (%) 19.5 - 22.0
Color (Gardner Number) 5 Max
Density (g/ml) 1.0 - 1.1

International Regulatory Listings

  • TSCA (US) Yes

  • DSL (Canada) Yes

  • REACH (EU) Yes

  • AICS (Australia) Yes

  • KECI (South Korea) Yes

  • IECSC (China) Yes

  • ENCS (Japan) Yes

  • TCSI (Taiwan) Yes

  • NZloC (New Zealand) Yes

  • PICCS (The Philippines) Yes

  • NDSL (Canada) No


REAXIS® C221 and its alternatives can be used as a homogenous tin catalyst in a wide spectrum of polyurethane and silicone applications including adhesives and sealants, elastomers and plastics, and coatings. Silicone-based applications for Dibutyltin Dineodecanoate include: acetoxy-, ethoxy- and oxime-based Room Temperature Vulcanizing (RTV) adhesives and sealants, polyethylene crosslinked silanes (PEX), and select silane modified polymers (SMPs). REAXIS® C221 and its analogues are preferentially used in formulations with oxime functionality. In regard to polyurethane applications, REAXIS® C221 can be used for most related applications including coatings, adhesives and sealants, elastomers, and foams. REAXIS® C221 is used in formulations utilizing either aliphatic or aromatic isocyanates and a wide range of polyether and polyester-based polyols.  Dibutyltin Dineodecanoate  is present on most global chemical inventory lists, making it a great choice for products with a multinational customer base. 


REAXIS® C221 is expected to be slower in reactivity compared to its methyl analogue REAXIS® C325 and faster than its octyl analogue, REAXIS® C318. These reactivity differences are mainly due to differences in tin metal loading for each product. Given the nature of a homogeneous tin catalyst, these reactivity differences can be affected by the key reactive raw materials used in the specific formulation. This reactivity difference is evidenced both in polyurethane and silicone chemistries in general, across all applications. In regard to silicone reactions, REAXIS® C221, like all tin-based catalysts, will catalyze the silanol/silane condensation reaction, acting as both a polymerization and crosslinking catalyst. As a polyurethane catalyst, REAXIS® C221, will preferentially catalyze the urethane reaction and to a lesser extent the water reaction, acting as a polymerization/gelation catalyst.  

Package & Storage

  • 44 lb (20 kg) plastic drums
  • 485 lb (220 kg) drums

REAXIS® C221 should be stored in the original packaging at moderate temperatures and kept from freezing. The container should be closed tightly after each use to maximize shelf life. Characteristic of most Sn (IV) organotins, the primary cause of instability would be hydrolysis. Hydrolysis results in the formation of tin oxide insolubles leading to deactivation of REAXIS® C221.

Safety and Handling

Before use of Reaxis products please refer to the relevant Safety Data Sheet (SDS) for safety and toxicological data as well as for the information on proper transportation, storage, and use. SDSs are available by request via our web site, contacting your local representative, or emailing direct to

Hazard Classification (US SDS)

Section Hazard Class Category Hazard Statement
A.5 germ cell mutagenicity 2 H341
A.7 reproductive toxicity 1 H360
A.9 specific target organ toxicity - repeated exposure 1 H372

Hazard Pictograms (US SDS)


Transportation Information (US SDS)

DOT IMDG ICAO Environment Hazard
UN Number UN 2788 UN 2788 UN 2788 hazardous to the aquatic environment
UN Proper Shipping Name Organotin compounds, liquid, n.o.s. ORGANOTIN COMPOUNDS, LIQUID, N.O.S. Organotin compounds, liquid, n.o.s.
Transport Class 6.1 6.1 6.1
Packing Group lll lll lll

Primary Composition Substance(s)

  • Stannane, dibutylbis[(1-oxoneodecyl)oxy]

Alternative Product(s) to Consider

This information is provided to the best of our knowledge but without obligation. Reaxis is not liable for any incorrect or missing information. This data sheet becomes invalid upon publication of a new version. Please contact us for the latest version.

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